1. Field of the Invention
The present invention relates to network design, and traffic analysis including evaluation of a communications network, for example a broadband communications network.
2. Description of the Related Art
Existing communications networks include nodes and circuits, also referred to as links, that interconnect the nodes. Certain nodes may be configured as source/destination nodes configured for introducing/outputting data traffic to/from the network; hence source/destination nodes are considered to “originate” traffic into the network and “sink” traffic from the network. Other nodes are configured as transit nodes (i.e., intermediate nodes) that only can switch traffic, and cannot originate or sink traffic.
An owner of a large scale communications network, for example a backbone network configured for transporting interexchange carrier traffic or wide area network traffic, sells or leases network resources by offering network access to the communications network in terms of a prescribed data rate, for example a prescribed leased bandwidth or a prescribed leased capacity. The sale or lease of network resources based on a prescribed capacity, for example continuous 10 Gigabit per second (Gbps) capacity, requires that the network owner employ network engineering during network deployment to estimate the data-carrying capacity of the large scale communications network.
Network design capacity typically is estimated during design of the network based on selection of hardware components and circuits having prescribed specifications relative to design criteria. For example, network engineers designing a network for deployment will estimate the network capacity based on prescribed specifications of the hardware components used to implement the nodes, and the bandwidth capacity of the circuits interconnecting the nodes. In particular, hardware components such as ATM switches, Ethernet (IEEE 802.3) switches, frame relay switches, microwave repeaters, satellite ground stations, etc. typically will specify their respective capacities (e.g., 100 Mbps ports, 1 Gbps ports, OC-48 SONET ports, etc.). As the hardware components and circuits are installed, typically the hardware components/circuits and their associated attributes (including network capacity attributes specified in the prescribed specifications) are added to a network inventory database, indicating the installed hardware components are available for network service. The installed hardware components/circuits are then provisioned for network service, enabling the installed hardware components/circuits to service network traffic. Hence, network capacity is affected as hardware components/circuits are added to the network.
The capacity of a large scale communications network in transporting network traffic (i.e., network capacity), however, cannot be precisely determined merely by identifying the prescribed capacity specifications of the installed hardware components. In particular, actual network capacity invariably is less than design estimates due to factors associated with deployment of the network. Determining network capacity becomes substantially more complex as the number of circuits and nodes increases in the network, and as network traffic increases. Hence, network owners encounter increasing difficulty in accurately assessing available network capacity for selling or leasing network resources, and for determining whether network expansion is required.